An electric field will cause an induced dipole in neutral atoms when present - I presume that if the field were strong enough the magnitude of the polarization could exceed a critical length and cause ...

I have been reading various articles on Renormalization group where they compute the flow of some parameter which becomes increasingly attractive and then say that parameter is responsible for Cooper ...

The term escape velocity is quite common to us. But we know velocity is a dimension dependent on the direction. But the escape velocity has same value irrespective of from where it is thrown from the ...

In a paper on the superlens, I came across the term of "transfer function". I understand that the transfer function relates the output to a given input, but I've been unable to find a formula for the ...

What is an effective potential in classical mechanics? I have read the wikipedia article and David Tong's lectures notes, but I didn't understand how an effective potential simplifies a situation or ...

I ask this question as the two seem to be very closely related and are sometimes taken to be one and the same (in the notion of microcausality in QFT), which has left me confused as to what meaning of ...

The commutator of generators of Lorentz transformation and translation is as follow:
$$[M^{\mu\nu},P^\sigma]=i(P^\mu\eta^{\nu\sigma}-P^\nu\eta^{\mu\sigma} ).$$
Then from this we usually say that the ...

Its commonly said that gauge bosons transform according to the adjoint representation of the corresponding gauge group. For example, for $SU(2)$ the gauge bosons live in the adjoint $3$ dimensional ...

I have seen in I.E. Irodov that if the permittivity is given as $\epsilon$ then we can find the capacitance as $$C = \frac{\epsilon A}{d}$$ but I wonder whether it is dimensionally correct or not and ...

What is the unitary matrix equivalent to the operation of a beam splitter?
I'm asking because I've seen different matrices used and was wondering if the term is just ambiguous or if there's an agreed ...

What is the difference between dynamics and kinematics of quantum field theory? I read that in QFT there is no possibility to keep the two things distinct because of a problem with the separability of ...

In "Research and Development for a Gadolinium Doped Water Cherenkov Detector" the phrase "forward peaking" is used to describe a signal. This comes up in lots of other contexts too, but I still can't ...

I have seen and read several times about the double slit experiment, that an electron (or even a molecule (!) as I found out later) behaves like a wave that swaps over those slits.
However I wonder ...

I have recently started studying the basic ideas of symmetry and group representation in order to understand the basic principles behind the standard model. I do follow the difference between a global ...

Why and how does negative velocity exist? I have read on the internet about negative velocity but I still don't understand how it can even exist since time is positive and so is length. By doing some ...

I have been asked in homework to solve the optical bloch equation for the initial condition of $\rho_{22}=0,\rho_{12}=0$. Professor gave a hint of the general equation and let us carry it from here. ...

The word "complete" seems to be used in several distinct ways. Perhaps my confusion is as much linguistic as mathematical?
A basis, by definition, spans the space; some books call this "complete" -- ...

In studying wave propagation through multilayers, the squared refractive index $n^2$ is a more pertinent parameter than $n$ itself. Is there a received name for $n^2$?
Of course, as long as there is ...

When working with realistic two-body hamiltonians, a direct diagonalization is almost always imposible. Thus one usually takes a procedure which yields an approximate solution. A well known approach ...